Evaluating the cost-effectiveness of ophthalmologic screening initiatives can guide decisions about when and where to implement screening. If done well, these analyses can help target scarce visual health resources in a way that maximizes societal well-being at a reasonable cost. The need for targeted visual health screening in the United States is increasing as the U.S. population ages because the epidemiology of major adult visual disorders is age-related. However, assessing the cost-effectiveness of visual screening is complicated by subpopulation differences in the routine use of visual screening services. Models that fail to account for this heterogeneity may lead to erroneous conclusions about where and when screening services are justified. In Aim 1 of this project, we will make substantial improvements to an existing visual health simulation model that will enable it to account for heterogeneous patient screening histories based on empirically observed patient data from the Beaver Dam Eye Study and the Los Angeles Latino Eye Study. The model will be unique in at least three important respects: (1) it will be the only cost-effectiveness model that includes the benefits of preventing multiple eye diseases with a single screening intervention;(2) it will be the only visual health screening model that evaluates the cost-effectiveness of a visual health screening intervention implemented in a realistic, mixed-age group population;and (3) it will be the only visual health model that incorporates real patient data at the individual level, which enables the model to simulate the benefit of screening among a mixed group of heterogeneous patients. In Aim 2, we will use the improved model to estimate the cost-effectiveness of visual health screening interventions when considering the benefits of preventing multiple eye diseases and accounting for patient differences in past service use, insurance coverage, and costs to screen. Finally, in Aim 3, we will use the results from our cost-effectiveness analyses to develop a user-friendly software tool that will enable findings to be disseminated to a wide range of decision makers, practitioners, and researchers in a way that is most meaningful in their individual setting. If successful, the project as a whole could lead to improvements in the targeting of visual health screening services and enhancements to the public welfare at a reasonable cost.